Release version 1.1.17 - Array duplicate prevention

Fixed persistent duplicate settings page by adding array-level duplicate
detection in addition to singleton pattern from v1.1.16.

Root Cause:
- WooCommerce calls woocommerce_get_settings_pages filter multiple times
- Even with singleton pattern, each filter call added settings instance to array
- Singleton prevented multiple class instances but not multiple array entries

Fixes:
- Settings page rendering twice despite singleton pattern in v1.1.16
- Filter adding same settings instance to array on repeated calls

Changes:
- Added duplicate detection loop in add_settings_page() before array append
- Uses strict comparison (===) to check if instance already in array
- Returns early if settings page already present, preventing duplicate

Technical Details:
- foreach loop iterates through existing $settings array
- Compares each element against cached self::$settings_instance
- Only appends to array if instance not found
- Complements singleton pattern with array-level protection
- Handles WooCommerce calling filter multiple times during page load

Updated Files:
- includes/class-wc-tpp-admin.php (added duplicate check in filter)
- wc-tier-and-package-prices.php (version 1.1.17)
- composer.json (version 1.1.17)
- CHANGELOG.md (v1.1.17 section)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

wc-tier-and-package-prices.php

@@ -4,7 +4,7 @@
  * Plugin Name: WooCommerce Tier and Package Prices
  * Plugin URI: https://src.bundespruefstelle.ch/magdev/wc-tier-package-prices
  * Description: Add tier pricing and package prices to WooCommerce products with configurable quantities at fixed prices
- * Version: 1.1.16
+ * Version: 1.1.17
  * Author: Marco Graetsch
  * Author URI: https://src.bundespruefstelle.ch/magdev
  * Text Domain: wc-tier-package-prices
@@ -23,7 +23,7 @@ if (!defined('ABSPATH')) {
 
 // Define plugin constants
 if (!defined('WC_TPP_VERSION')) {
-    define('WC_TPP_VERSION', '1.1.16');
+    define('WC_TPP_VERSION', '1.1.17');
 }
 if (!defined('WC_TPP_PLUGIN_DIR')) {
     define('WC_TPP_PLUGIN_DIR', plugin_dir_path(__FILE__));